D-brane instanton induced mu-terms and their hierarchical structure

TL;DR

This paper investigates how D-brane instanton effects generate mu-terms in intersecting D6-brane models, revealing a permutation symmetry and a naturally hierarchical eigenvalue structure without fine tuning.

Contribution

It demonstrates that D-brane instantons induce a mu-term matrix with permutation symmetry and hierarchical eigenvalues, providing insights into fermion mass hierarchies in string models.

Findings

Mu-term matrix exhibits permutation symmetry.

Eigenvalues of the mu-term matrix have a hierarchical structure.

Hierarchy arises without fine tuning.

Abstract

We study the mu-term matrix of Higgs pairs induced by the D-brane instanton effects in intersecting D6-brane models compactified on T6. It is found that the mu-term matrix has a certain permutation symmetry and its eigenvalues have large hierarchical structure without fine tuning.